Be-horsian

According to the Old English Dictionary:

be-horsian

p. ode, ade, ude; pp. od, ad, ud To deprive of a horse; equo privare :-- Ðá eode se here to hyra scipum ... and hí wurdon ðǽr behorsode then the army went to their ships ... and they were there deprived of their horses, Chr. 886; Th. 152, 28, col. 3. DER. horsian. be-horsian